Letter to the Editor August 15, 2013

A decade ago, on Aug. 14, 2003, just before 3:10 p.m. CDT, 50 million people in parts of eight U.S. states and Ontario, Canada, were suddenly in the dark. A tree limb in Ohio came in contact with an electric transmission line causing 531 electric power generators including 19 nuclear energy units to trip off line removing 62,000 megawatts of electric power from the grid in what has become known as “The Great Blackout of ’03.” Eleven people died. The blackout caused a $6 billion loss to the North American economy.

TVA and the more than 9 million people who rely on TVA power were not affected due to the distance from the center of the disturbance in Ohio. However a digital fault recorder at the Volunteer 500 kilovolt substation in Tennessee recorded a near instantaneous increase in frequency from 60.02 to 60.2 hertz at 4:10:41 just after the northeast island separated from the rest of the Eastern Interconnection. This frequency increase was properly managed by TVA’s Balancing Authority as part of normal processes.

Since all electric utilities in the Eastern Interconnection are electrically tied together operating at the same frequency, it took a carefully coordinated effort to bring the grid back online.

Power reliability is TVA’s No. 1 customer goal. Highly skilled power crews do preventive maintainence to keep vegetative growth away from transmission lines as well as respond 24-7 to emergencies to provide reliable electric power.

For 13 consecutive years, TVA has achieved a 99.999 power reliability factor. This enables people in the Tennessee Vally to enjoy life at home, work and leisure activities.

Thanks, to the men and women of TVA and 155 local power companies who work day and night to keep the lights on in The Valley.